.U_box{
    width:5rem;
    height:4rem;
    margin:0 auto;
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    align-items: center;
    margin-top: 1rem;
    border-radius: 0.1rem;
    padding: 0.2rem;
    box-shadow: 0 0 0.1rem rgba(0, 0, 0, 0.3);
    background-color: #fff;
}
.U_xiao{
    display: none;
}
.U_xian{
    display: block;
    color: red;
    font-size: 0.25rem;
    text-align: center;
}